Alright, let's work through 8420 times 4857 step by step
8420 × 4857 = 4857 × (8420)
+ 4857 × 0 giving us 0
+ 4857 × 20 that is equal 97140
+ 4857 × 400 that is equal 1942800
+ 4857 × 8000 resulting in 38856000

= 40895940
